The subject matter of the present invention relates to a drop off apparatus for a perforating gun capsule charge carrier.
Perforating guns are disposed in oil well boreholes for perforating a formation traversed by the borehole, a well fluid being produced from the perforated formation. The perforating gun includes a carrier and a plurality of capsule charges mounted on the carrier. When the charges detonate, the formation is perforated. The carrier is often deformed as a result of the detonation of the capsule charges. Since the well dimensions are often very small, it is risky if not impossible to retrieve a distorted or deformed carrier strip from the well. In some cases, it is preferable to drop the perforating gun to the bottom of the well after detonating the capsule charges mounted on the carrier. Prior art perforating gun systems include a dropping mechanism which is designed to drop the perforating gun to the bottom of the well. In the prior art system, the dropping mechanism dropped the head of the perforating gun, or part of it, to the bottom of the well along with the charges. This abandonment of the perforating gun head can be very expensive. In addition, special hardware is often needed to operate the dropping mechanism on the prior art systems.